Photochemical reaction of unsaturated ethers with hydrogen sulfide



Patented Sept. 19, 1950 PHOTOCHEMICAL REACTION OF UNSATU- RATED ETHERSWITH HYDROGEN SUL- FIDE William E. Vaughan and Frederick F. Rust,

Berkeley Calif., assignors to Shell Development Company, San Francisco,Calif., a corporation of Delaware No Drawing. Application March 28,1945, Serial N0. 585,388

4 Claims.

The present invention relates to a process for the preparation ofcertain organic sulfur-containing compounds, some of which are novel.More particularly, the invention pertains to a novel process for theinteraction of hydrogen sulfide with unsaturated, symmetrical orunsymmetrical ethers. The word ether, as employed herein and in theappended claims, refers both to the oxy-ethers and to the thio-ethers.In one of its more specific embodiments the invention covers thepreparation of polyethers by reacting hydrogen sulfide with symmetricalor unsymmetrical oxyethers or thioethers containing unsaturated linkagesof aliphatic character in each of the radicals attached to the etheroxygen atom or to the thioether sulfur atom. The invention is alsodirected to a novel method of eifeotin'g a controtlled reaction betweenhydrogen sulfide and oxyethers in which each of the organic radicalsattached to the ether oxygen atom contains at least one saturatedlinkage of aliphatic char acter, i. e. a double or triple bond, which ispreferably between the carbon atom farthest removed from the etheroxygen atom, to produce novel addition products of a predeterminedcharacter. The invention also includes a certain novel class of linearpolyethers which may be defined as havin recurring structural units ofthe general formula in which m and n are integers.

This application is a continuation in part of our pending patentapplication Serial No. 385,701, filed March 28, 1941, now Patent2,398,479.

It is known that mercaptans and thioethers may be produced by subjectingmixtures of hydrogen sulfide and unsaturated hydrocarbons to elevatedtemperatures in the neighborhood of from 200 C. to 750 C. In someinstances, such reactions were effected at superatmospheric pressures.When the reactions are effected at such temperatures and pressures, thesulfhydryl group attaches to the unsaturated carbon atom containing thelesser number of hydrogen atoms linked thereto. In other words, as setforth by J ones'and Reid, Jour Amer. Chem. Soc., vol. 60, pp. 2452-2455,the addition takes place according to Markownikofis rule. Therefore,when terminally unsaturated olefins are thus reacted withhydrogensulfide, the reaction product pre- 2 dominates in secondarymercapt-ans and/or secondary thioethers.

It has now been discovered that unsaturated ethers of the class morefully described hereinbelow may be reacted with hydrogen sulfide toeffect rapid, efficient and directional conversion to certain mercaptansand/0r polyetherss This conversion occurs via the so-called abnormaladdition, i. e. contrary to the course suggested the Markownikoif rule.According to the process of the present invention, the abnormal additionof hydrogen sulfide to the unsaturated ethers may be effected in theabsence of free oxygen, air, ozone or peroxides and, in fact, in theabsence of any compound or substance the presence of which washeretofore considered necessary for promoting, sensitizing or catalyzingthe mentioned abnormal addition of hydrogen sulfide to unsaturatedhydrocarbons. Also, contrary to the teachings of the prior art, suchinteraction of hydrogen sulfide with the unsaturated ethers may beeffected without the necessity of resorting to high temperatures andelevated pressures heretofore deemed essential to promote or effect thedesired reaction between unsaturated hydrocarbons and hydrogen sulfide.

Broadly stated, the process of the present invention resides in thephotochemical addition of hydrogen sulfide to unsaturated oxyethers orthioethers under the deliberate influence of ultraviolet radiations,this reaction being effected without the necessity of applying heat, andbeing preferably realized at normal temperatures, i. e. in theneighborhood of from about 25 C. to about 15 C., or even at considerablylower temperatures. More particularly stated, the reaction is effectedunder the influence of light rays having wave-lengths below about 2900to 3000 Angstrom units. It has been still further discovered that theselight rays strongly catalyze the photochemical addition of hydrogensulfide, this reaction being preponderantly, if not wholly, contrary tothe course suggested by Markownikoff for the addition of hydrogenhalides, and in accordance with the rule proposed by Posner lBerichte,38, 646 (1904)] concerning the addition of mercaptans to double bonds,namely that the sulfur of the mercapto group normally becomes attachedto the carbon atom carrying the most hydrogen atoms. Therefore, thephotochemical reaction taking place under the deliberate influence ofultraviolet radiations offers a direct method for obtaining primarymercaptans and/or primary polyethers from oxyethers,

thioethers or oXy-thioethers containing a terminally unsaturated carbonatom.

The process of the invention is applicable to the reaction of hydrogensulfide with any ether (i. e. oxyand/or thioether) which contains one ormore olefinic and/or acetylenic linkages. In other words, any ethercontaining one or more unsaturated linkages between two carbon atoms ofaliphatic character may be reacted with hydrogen sulfide in accordancewith the process of the present invention.

One group of such unsaturated ethers comprises the aliphatic oxyethersin which only one of the aliphatic radicals attached to the ether oxygenatom contains an unsaturated linkage. Examples of such ethers are ethylvinyl ether, ethyl propenyl ether, methyl isopropenyl ether, ethylisopropenyl ether, methyl allyl ether, ethyl allyl ether, n-propyl allylether, isopropyl allyl ether, 4-ethoxy-butene-1, 6-ethoXy-heXene-1,gammaethoXy-alphabutylene, methyl propargyl ether, ethyl propargylether, etc., and their homologs and analogs. The above unsaturatedethers and their various homologs may be substituted by straight-chain,cyclic and/or heterocyclic radicals, as well as by halogens. Thefollowing are examples of such halogenated unsaturated ethers which maybe reacted with hydrogen sulfide in accordance with the process of thepresent invention: ethyl alpha-chlorovinyl ether, ethyl betachlorovinylether, ethyl alpha,beta-dichlorovinyl ether, methyl 'betabeta-dichlorovinyl ether, ethyl beta,beta-dichlorovinyl ether, ethylbeta,beta-dibromovinyl ether, -methoxy-3,3-dichloropropene-l,2-ethoxy-3,3-dichloropropene-1, 2-propyloxy 3,3 dichloropropene-l, ethylgammachloroallyl ether, methyl gamma-bromoallyl ether, ethylbeta,gamma-dibromo-allyl ether, and their homologs and analogs.

Another group of suitable unsaturated ethers which may be employed as astarting material comprises the aliphatic thioethers in which only oneof the radicals attached to the thioether sulfur atom contains anunsaturated linkage. Examples of this group are: ethyl vinyl sulfide,ethyl isopropenyl sulfide, and the like, and their homologs and analogs,as well as suitable substitution products.

'Still another group of ethers which may be employed as the primarymaterial comprises or includes the aliphatic oxyethers in which bothradicals attached to the ether oxygen atom contain unsaturated olefinicand/or acetylenic linkages. The following are illustrative examples ofsuch poly-unsaturated oxyethers: divinyl ether, diisopropenyl ether,diallyl ether, dicrotyl ether, dimethallyl ether, di(alpha-methyl-allyl)ether, (butene-l-yl-B) (butene-Z-yl-l) ether, di(pentene-2-yl-4) ether,dihexenyl ethers, allyl(2- methyI-pentenel-yl-Z) ether, allyl linallylether, etc, and their homologs, analogs and suitable substitutionproducts, such as the halogenated derivatives of the type ofhexachlorodivinyl ether, di(beta-bromoallyl) ether,di(beta,gamma-diiodoallyl) ether, and the like. Also, the correspondingthioethers in which each radical attached to the sulfur atom contains anunsaturated linkage between two carbon atoms of aliphatic character maybe reacted with hydrogen sulfide in accordance with the process of thepresent invention, The following arev illustrative examples of thisgroup of thioethers: divinyl sulfide, di(betachlorovinyl) thioether,diallyl sulfide, dicrotyl sulfide, dimethallyl sulfide. dihexenyl 4sulfides, and the like, and their homologs and analogs.

The ethers employed as the starting material may also contain more thanone ether oxygen atom and/or thioether sulfur atom, this group ofunsaturated ethers being represented by compounds of the type ofl,2-bis(vinyloxy) ethane, 1,3 bis(vinyloxy) propane, 1,2 bis(allyloxy)ethane, and the like, as Well as by unsaturated disulfides, e. g.divinyl disulfide.

The invention is particularly applicable to the reaction of hydrogensulfide with unsaturated ethers (i. e. oxyethers and thioethers) inwhich one or both radicals attached to the oxygen or sulfur atom have aterminal aliphatic unsaturated linkage. When such unsaturates arereacted with hydrogen sulfide in accordance with the process of thepresent invention, 1. e. photochemically and under the influence ofultraviolet radiations, the reaction product predominates in or consistsof primary mercaptans and/or primary thioethers.

As stated, a group of unsaturated ethers which may be employed as theprimary material comprises or includes the aliphatic oxyethers orthioethers (and their products of substitution) which containunsaturated linkages in alpha and omega positions, 1. e. in terminalpositions in each of the radicals attached to the ether oxygen (orsulfur) atom. Because of the fact that the addition of hydrogen sulfideto unsaturated organic compounds, when effected photochemically andunder the influence of ultravoilet radiations, is via the so-calledabnormal addition discussed above, the sulfhydryl radicals will attachto the terminal carbon atoms which carry the greatest number of hydrogenatoms. When each of the radicals of the ether contains a terminal doubleor triple bond, the treatment of such ethers with hydrogen sulfide inaccordance with the process of the present invention will form areaction product containing primary dimercaptans. cules of thepolyunsaturated ether to produce primary ethers possessing a highmolecular weight. For instance, diallyl ether may be reacted withhydrogen sulfide to produce high molecular weight compounds whichcontain both ether oxygen atoms and thioether sulfur atoms in the chain.Instead of employing aliphatic straight-chain polyunsaturated ethers, itis also possible to use branched chain ethers as well as etherscontaining alicyclic, aryl, aralkyl and similar radicals, which may ormay not be further substituted, e. g. halogenated, provided such etherscontain at least one unsaturated linkage between two carbon atoms ofaliphatic character. In order to produce the above-mentioned highmolecular weight addition compounds, the unsaturated ethers to betreated in accordance with the process of this invention should have atleast one such unsaturated linkage of aliphatic character in each of theradicals attached to the ether oxygen atom (in the case of oxyethers) orto the thioether sulfur atom (when the starting material is athioether). However, other polyunsaturated ethers may also be used toproduce branched chain polyethers having high molecular weights.

The reaction of hydrogen sulfide with the above-defined class ofunsaturated ethers under the influence of ultra-violet radiations may beeffected in the vapor phase, in the liquid phase, or in a two-phaseliquid-vapor system. Since the abnormal addition of hydrogen sulfide ac=These in turn react with additional mo1ecording to the present processoccurs photochemically, no heating is necessary. In fact, and in view ofthe exothermic character of the addition reaction, resort to cooling isfrequently advisable, if not essential. The reaction may be realized atatmospheric temperatures (i. e. between about C. and about C.), or atsomewhat higher temperatures. It may frequently be effected attemperatures as low as 0 -C. and lower.

The photochemical reaction may be effected at any pressure. However, itis generally preferable to employ superatmospheric pressures which areat least sufficient to maintain the reactants, or at least theunsaturated ether, in the liquid state. This is because the conversionrate appears to be accelerated when the reaction is effected in theliquid state.

Th eifective wave-lengths of ultra-violet light which promote thedesired abnormal addition of hydrogen sulfide appear to lie in thatpor-' tion of the spectrum which is below about 3200 Angstrom units, andmore particularly in the region of about 2900 Angstrom units and below.In fact, the interposing of an ordinary window glass filter (which has alower limit of transmission of about 3300 Angstrom units) or of a Pyrexglass filter having a lower transmission limit of about 2900 to 3000Angstrom units, in the path of light coming from a source emittingultra-violet radiations will cause a substantially complete inhibitionof the reaction unless some sensitizer, such as organic peroxides orketones, is added. On the other hand, the use of quartz vessels for thereaction according to the process of the present invention allowsefficient addition of hydrogen sulfide due to the fact that quartztransmits ultra-violet rays considerably below 2900 Angstrom units.

The addition reaction between hydrogen sulfide and the unsaturatedethers occurs very rapidly when effected under the influence ofultra-violet rays, particularly When relatively low-boiling unsaturatedethers, such as the lowboiling m'onoor polyunsaturated oxyethers, arethus treated in the liquid phase and when low wave-lengths of about 2900A. U. and below are employed. initial induction period during which nowsubstantially no reaction occurs. This is particularly true when vaporphase reactions are effected, especially in the presence of certainimpurities which affect adversely the reaction rate. The length of theinduction period, if such occurs, varies depending on a number ofconditions, such as the specific unsaturated ether em ployed, presenceor absence of a liquid phase, concentration of the reactants in thereaction zone, presence or absence of impurities and/or added surfacesin the reaction zone, etc. Also, other conditions being equal, a changein the intensity of the effective wave-lengths of the ultra-violetradiations will vary the rate of the abnormal addition of the hydrogensulfide and, in the case of the reaction of hydrogen sul- In some cases,however, there is an fide with polyunsaturated ethers, the molecularweight of the resultant polyethers, i. e. the degree of additionattained.

The reaction may be effected in a batch, intermittent or continuousmanner. When effected by the batch method, the reactants may beintroduced into a suitable container which is then illuminated withultra-violet light for a period compounds which may be Pyrex glass willnot permit any substantial transmission of the effective light waves,viz. those in the neighborhood of 2900 to 3000 Angstrom units and below,it is preferable to construct the container of quartz or other suitablelight transmitting materials, e. g. calcium fluoride, or at least toprovide such container with an opening or window of quartz, calciumfluoride, or the like, through which the interior may be illuminatedwith ultra-violet rays. In case of a continuous process the reactants,viz. hydrogen sulfide and the unsaturated ether, such as the aliphaticoxyethers in which each of the aliphatic radicals attached to the-etheroxygen atom contains a terminally-positioned double bond, may beconveyed, either in a liquid or vapor state, or both, through theinterior of a reaction chamher. This latter may be of sufficient lengthso as to permit adequate residence time for the reactants. The reactantsin the reaction chamber are i then subjected to ultra-violet radiationsemanating from a source or sources disposed within or without thechamber. In the former case, the reactor may be-constructed of steel orthe like, the source-of the ultra-violet radiations being disposed inthe path of the moving reactants. Instead of introducing both of thereactants together, it is also possible to convey one of the reactants,for example the unsaturated ether, through the whole length of thereactor tube, while feeding in the other reactant, e. g. hydrogensulfide, either in the liquid or the vapor state, at variousintermediate points. This permits control of the reaction temperatureand of the concentration of the reactants in the reaction zone. Thedischarged reaction products may be treated by any known or suitablemeans or methods for the separation and recovery of the desired additionand/or polyaddition products.

The addition reaction between hydrogen sulfide and the oxyethers inwhich each of the radicals attached to the ether oxygen atom contains anunsaturated linkage between the carbon atoms farthest removed from theoxygen atom results in the formation of novel and valuable generallyrepresented by the formula R [SCHzVR2ORaOH2 IR4 I wherein R2 and R3represent like or different" non-aromatic, substituted or unsubstitutedhydrocarbon radicals, m is an integer, R1 repre- 1 sents the hydrogenatom or' the radical CH2R5-;-O-R6=CII2, and R4 represents the sulfhydrylradical or the radical S OHP(( 'J)-O 'J) CHP in which m and n areintegers. The terminal sulfur atom of such linear polyethers issatisfied either by the hydrogen atom or by an alkenoxy radical attachedto the sulfur atom via a primary carbon atom. while the other end ofsuch linear polyether is terminated by the sulfhydryl radical or by aradical having the general formula wherein k and p are integers.

A particularly useful subclass of the novel compounds comprises thelinear polyethers which may be defined as having recurring structuralunits of the general formula in which m and n are integers and R1through R4 each represent th hydrogen atom, a halogen atom, or an alkyl,preferably lower alkyl, radical, e. g, methyl, ethyl, propyl, etc.radical. The products formed in accordance with'the process of thepresent invention by the interaction of divinyl ether with hydrogensulfide may be considered as specific examples of polyethers of thissubclass. Depending on the degree of addition reaction, the productsformed by the interaction of hydrogen sulfide with divinyl ether (inaccordance with the process of this invention) will predominate in orconsist of the following addition products:

This group of compounds may be exemplified by the general formula RES(CH2): O-(CHz)3]n wherein n is an integer, R1 represents 'the hydrogenatom or the radical and R2 represents the sulfhydryl radical or theradical --S(CH2) 3OC H2CH=CI-I2.

It is to be noted that in all of the novel compounds defined herein thethioether sulfur atom is attached to two carbon atoms .both of which areof primary character. Also, the sulfhydryl radical, if such is presentat one or both ends of the linear polyether compound, is always attachedto a primary carbon atom.

Depending on their molecular weights (and, to some degree, on thestarting unsaturated oxyethers employed), the novel class of polyethersrange from compounds (or mixtures of such compounds) which are veryfluid, through those which areoleaginous or viscous, and to compoundswhich are wax-like solids. The prop- 8 i erties possessed by these novelpolyether com pounds adapt them admirably for various uses. They areexceptionally well suited as a synthetic lubricating oil, syntheticlubricating grease, or as a coating or impregnating material alone or insolution together with solvents and/or other compounding agents. Theyare also satisfactory as blending agents in lubricants (e. g. minerallubricants) including greases, as plasticizers, hydraulic fluids andcoolants, as well as ingredients in the manufactur of cosmetics,polishes, soaps, and for many other uses which will be evident fromtheir chemical and physical char-- acteristics. For example, certain ofthe normally liquid compounds of the above-defined class of novelpolyethers (as well as mixtures of such novel polyethers) have molecularweights, pour points, viscosities, viscosity indices and oxidationstabilities which render them exceptionally adaptable for use assynthetic lubricating oils, or at least as ingredients of such oils. Onthe other hand, the wax-like solid polyethers of the above-defined classof novel compounds maybe readily employed as synthetic greases, in themanufacture of cosmetics, etc.

The invention is illustrated by the following specific examples, itbeing understood that there is no intention of being limited by anydetails thereof since many variations may be made.

Example I Equimolar quantities of hydrogen sulfide and diallyl etherwere introduced in the liquid state into a quartz bomb tube which wassealed under a high vacuum. The tube was then warmed to about 0 C.,disposed in a quartz container packed with ice, and subjected toillumination from a 400-watt quartz mercury arc lamp disposed at adistance of about 6 inches from the bomb. The irradiation was continuedfor about eighty minutes. The volume of the solution in the bombdecreased about 15%, most of this contraction occurring during the first20 minutes of irradiation. The reaction product was a waterwhite liquidwhich was distilled to a temperature of about 235 C. under a pressure ofabout 2.3 cm. (absolute) to separate the relatively lighter boilingconstituents, which amounted to about 8% by weight of the total, hadboiling temperature of about C., and a strong mercaptan odor. Iheresidual fraction remaining from the aforesaid distillation was found tohave the following properties:

Molecular weight (cryo. benzene) 674 Sulfur, per cent by weight 24.8Mercaptan, as sulfur, per cent by weight 5.1

From the above and other'analyses it appears that this polyadditionproduct, on the average, has the following structural formula:

This product has a molecular weight of 660, a sulfur content of about24% by weight, and a mercaptan content (as sulfur) of 4.85% by weight.

Molecular weight (cryo. benzene) 584: Mercaptan, as sulfur, per centweight 9.2 1 Micro pour point, C 43 Viscosity at 100 F., in centistokes52.0 Viscosity at 210 F., in centistokes 10.1 7 Viscosity Index 152Density, D4 1.0766 Sulfur, per cent by weight 24.1

From the above and other analyses it appears that this residualpolyether product has the following average structure:

The difference in the results obtained in Examples I and II give anindication as to the variations obtainable in the product by changes11.1

the operating conditions.

Example III Molecular weight (cryo. benzene) 661 Sulfur, weight per cent23.1 Mercaptan, as sulfur, weight per cent 7.8 Micro pour point, C -35Viscosity at 100 F., in centistokes 62.71 Viscosity at 210 F., incentistokes 10.01 Viscosity Index 136 Viscosity (S. A. E. No.) 20 Yield,weight per cent 83 From the above, it appears that this methallylether-hydrogen sulfide addition product has the followingaveragestructure:

I CH3 Example IV Substantially equimolar amounts of liquefied hydrogensulfide and divinyl ether were introduced into an evacuated quartz bombtube which n was then sealed and disposed in a quartz container packedwith ice. The reactants in the tube were then subjected to illuminationfrom a 100-watt quartz mercury arc lamp disposed at a distance of about6 inches from the bomb. The

reaction proceeded very rapidly, the volume of 65 the solution in thebomb decreasing by about 30 after three minutes of irradiation. At theend of about 7' minutes, a white, semi-solid material began to form nearthe bottom of the reactor. The irradiation was continued for a totalperiod of 10 minutes, at the end of which the reaction mixture washeated to 240 C. at a pressure of about 2 cm. (absolute), resulting inthe distillation of approximately 7.3% oi the mixture. The residualfraction, upon standing for a few hours, became a white, somewhat greasysolid which was found tohave the following properties:

Molecular weight (cryo. benzene) 1000 to 1100 Sulfur, weight per cent32.1

Mercaptan, as sulfur, weight per cent 4.3

Micro pour point, C to 50 Viscosity Index 129 Yield. weight per cent 93Example V In order to determine the effect of the molar ratio of theunsaturated ether to hydrogen sulfide on the polyether composition, foursolutions of diallyl ether and hydrogen sulfide, in which the moleratios of the ether to the hydrogen sulfide were 0.5 1, 1:1, 2: 1 and4:1, respectively, were-prepared, and each solution was thensubjectedfor a period of one hour to irradiation with ultra-violet rayswith the lamp and under theconditions described in Example I. Thereafterthe reaction products from each of the four runs were separatelydistilled to recover two fractions;

viz. one (Fraction A) distilling between 200 C. at about 13 cm. of Hgpressure (absolute) and 240 C. at about 1 cm. pressure, and the second(Fraction B) boiling above said last-mentioned temperature and pressure.These fractions were then separately analyzed. The following two tablespresent the properties of these fractions:

Fraction A Mole Ratios Used 0.521 2:1 4:1

Molecular weight (cryabenzene) 188 212 218 Sulfur, weight percent 9 15.114 0 Mercaptan, as sulfur, weight percent 26 2 0.2 0 02 Viscosity Index130 108 Yield. weight percent 34 36 Fraction B Mole Ratios Used 0.5:11:1 2:1 4:1

Molecular weight (cryo. henzene) 488 674 408 346 Sulfur, weight percent26.9 24. 8 18. 9 17.2 Mercaptan, as sulfur, weight percent 8.0 5. 1 0.05 0. 02 Viscosity Index 152 152 161 162 Yield, weight percent 50 92 18A comparison of. the above results indicates that changing the .moleratio of the ether to the hydrogen sulfide has but little eifect ontheprop- Example VI Three'separate runs were conducted in each'of whichequimolar amounts of diallyl ether and hydrogen sulfidewere placed inthe liquid state" in a quartz reaction tube which was thereafter sealed,placed in ice bath, and irradiated with light emanating from a quartzmercury arc lamp.

The contents of the first tube were thus i1lumi-' nated for a period of5 minutes, while the illuminations of thesecond and third tubes wereconducted for 10' minutes and 2 hours, respectively. The reactionmixtures obtained in each of the tubes were then separately distilled inthe following manner: The reaction mixture was first heatedatatmospheric pressures to a temperature 11 of 200 C. The distillate thusproduced constituted Fraction I. The residue was then again heated butat a pressure of about 13 cm. (absolute). The distillate thus producedconstituted Fraction II. The residue from the second distillation wasreheated to 240 C. at about 1 cm. pressure to produce an overheadFraction III, while the residue constituted Fraction IV. The yields ofthe various fractions thus produced, as

The oxidation pages 85 and 87 of the Papers Presented before.

the Petroleum Division of the American Chemical Society--Symposium onBench Scale Techniques, September 11-15, 1944, New York, New

well as their refractive indices, are presented in York. According tothis method, and operating the following table: at a temperature of 180C., the total residue was Fraction Illumination Time, Minutes 1 2 3 4Percent Percent Percent P t N-ZO/D W N-/D W N-20/D w N-20/D Example VIIfound to be 87% by weight, while the acetone- The apparatus employed inthis run consisted msoluble portlon of thls resldue Was 14% by of a 500cc. 3-neck flask equipped with a condenser, a quartz thimble holding al00-watt mercury arc lamp projecting downwardly from the center neck toa point about 0.5 cm. above a sintered glass bubbler built into thebottom of the fiask. Approximately 180 cc. of divinyl ether wereintroduced into the fiask, which was maintained at a temperature ofabout 0 C. The contents of the flask were then illuminated with theabove-mentioned lamp and approximately 0.28 moles of hydrogen sulfidewere bubbled into the liquid divinyl ether at a rate of approximately220 cc. per minute. About 15 minutes after the starting of the run asmall amount of a white solid began to form on the walls of the flask.At the end of the run the reaction mixture was distilled. After removalof the unreacted divinyl ether approximately of the remaining reactionmixture boiled above 240 C. at a pressure of about 1 cm. (absolute).This addition product was a liquid having a viscosity index of 144.

Example VIII Substantially equimolar amounts of diallyl sulfide andhydrogen sulfide were introduced in the liquid state into a quartzreaction tube, the mixture being then subjected to irradiation from aquartz mercury arc lamp. The polythioether compound produced, withrespect to color, viscosity and pour point, resembles the additionproduct obtained by the interaction of diallyl ether with hydrogensulfide. I

Example IX The residual fraction from distilling the products ofreaction obtained in Example I, which distillation was conducted under apressure of about 2.3 cm. absolute to a temperature of about 235 C., wastested for its extreme pressure lubricating properties. This wasdetermined by running the residual product in the '4-Ball machine de-'scribed in Engineering, vol. 136 (1933), p. 46, for 2 hours at '7 kg.load and at a temperature of 130 C; The scar diameters on the top ballswere then measured and found to be equal to 0.33 mm., thus indicatingthe exceptionally low wear and friction characteristics of the product.

The same residual fraction was also tested to determine its oxidationresistance stability. The test employed was that described in Ind.

weight.

The oxidation stability may be increased materially by the eliminationof the terminal olefinic double bond and/ or of the terminal group.Also, anti-oxidants may be added to improve the stability.

Example X Diallyl ether and hydrogen sulfide (used in a volumetric ratioof 2:1) were mixed in an evacuated quartz tube, the mixture being thensubjected, for a period of 15 minutes and at a temperature of from 0 C.to 10 C., to light emanating from a quartz mercury arc lamp. The liquidreaction product had a molecular weight of 285, and approximately 25.9%by Weight 0 V sulfur.

Ea'ample XI When hydrogen sulfide is reacted with 1,2- bis(divinyloxy)ethane under the deliberate infiuence of ultra-violet radiations ofbelow about 2900 to 3000 Angstrom units, the reaction product containshigh molecular weight addition products having recurring structuralunits of the general formula We claim as our invention:

1. In a process for the production of an unsaturated linear polymer, thesteps comprising subjecting diallyl ether and hydrogen sulfide, mixed ina molar proportion of from 1 to 4 moles of ether per mole of hydrogensulfide and maintained in the liquid phase, to light radiations havingwave lengths below 3000 Angstrom units until products boiling above 240C. at 1 cm. pres sure are produced, and recovering such products.

2. In a process for the production of an unsaturated linear polymer, thesteps comprising subjecting divinyl ether and hydrogen sulfide,

mixed in a molar proportion of from 1 to 4 moles of ether per mole ofhydrogen sulfide and maintained in the liquid phase, to light radiationshaving wave lengths below 3000 Angstrom units until products boilingabove 240 C. at 1 cm. pressure are produced, and recovering suchproducts.

3. In a process for the production of an unsaturated linear polymer, thesteps comprising subjecting a dialkenyl ether containing both doublebonds in the form of 7 terminal =CH2 subjecting hydrogen sulfide and adiolefinically 10 unsaturated aliphatic compound in which the doublebonds are contained in two hydrocarbon radicals separated by at leastone member of the group consisting of the thio and oxy groups, mixed inmolar proportions of from 1 to 4 moles of diolefinio compound per moleof hydrogen sulfide and maintained in the liquid phase, to lightradiations having Wave lengths below 3000 14 Angstrom units untilproducts boiling above 240 C. at 1 cm. pressure are produced, andrecovering such products.

WILLIAM E. VAUGHAN. FREDERICK F. RUST.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,118,995 Waldmann et al. May 31,1938 2,142,145 Patrick Jan. 3, 1939 2,332,165 Ott Oct. 19, 19432,392,294 Rust et a1. Jan. 1, 1946 2,398,479 Vaughan et a1 Apr. 16, 1946

4. IN A PROCESS FOR THE PRODUCTION OF AN UNSATURATED LINEAR POLYMER, THESTEPS COMPRISING SUBJECTING HYDROGEN SULFIDE AND A DIOLENFINICALLYUNSATURATED ALIPHATIC COMPOUND IN WHICH THE DOUBLE BONDS ARE CONTAINEDIN TWO HYDROCARBON RADICALS SEPARATED BY AT LEAST ONE MEMBER OF THEGROUP CONSISTING OF THE THIO AND OXY GROUPS, MIXED IN MOLAR PROPORTIONSOF FROM 1 TO 4 MOLES OF DIOLEFINIC COMPOUND PER MOLE OF HYDROGEN SULFIDEAND MAINTAINED IN THE LIQUID PHASE, TO LIGHT RADIATIONS HAVING WAVELENGTHS BELOW 3000 ANGSTROM UNITS UNTIL PRODUCTS BOILING ABOVE 240* C.AT 1 CM. PRESSURE ARE PRODUCED, AND RECOVERING SUCH PRODUCTS.